This invention relates to a drive apparatus for motor and manual operation of a lock or locking cylinder.
A lock drive is known from DE 196 01 424 A1. The gear motor is connected with the turning handle so as to rotate in unison. To supply power to the motor, rubbing contacts are provided. The gear is formed by an epicyclic gear disposed coaxially to the motor and the driveshaft. In order to permit motor rotation of the driveshaft, the gear motor is connected with the escutcheon by an electromagnetic device so as to rotate in unison.
The known apparatus requires a lot of space due to its large axial length, the electromagnetic locking device and the like. Its reliability also leaves something to be desired. For example the rubbing contacts can soil easily.
CH 669 425 A5 discloses a motor drive for a cylinder lock which is operable additionally by hand using a key. In this hand operation the motor drive is coupled via a coupling.
DE 33 10 822 C2 describes the formation of a toothed gear as a coupling, the coupling/uncoupling being effected with axially displaceable coupling wheel 21. Further, DE 297 03 559 U1 describes an electromechanical coupling between the operating knob, and the lock.
WO 96/07807 A1 discloses the principle of coupling from the turning handle to the adjusting mechanism via an internal toothing.
This invention is directed to a lock drive apparatus which works reliably while requiring little space and having a simple structure.
According to the invention, a gear motor is connected with the escutcheon so as to rotate in unison. Thus, no rubbing contacts or the like are necessary for energizing the motor.
The rotation of the turning handle (e.g. knob) rotatably mounted on the escutcheon is transmitted to the driveshaft by a driving toothed wheel according to the invention. The permanent torque transmission from the turning handle to the driving toothed wheel can be effected e.g. by an internal toothing on the turning handle which meshes with the driving toothed wheel.
By the driving toothed wheel the gear motor is at the same time connected with the driveshaft according to the invention in order to permit motor operation of the lock or locking cylinder. For this purpose, a coupling is provided which connects the gear motor with the driving toothed wheel when current is supplied.
In the currentless, i.e. uncoupled, state of the gear motor, the turning handle can be operated manually with low expenditure of force. Since the turning handle is always connected with the driving toothed wheel so as to transmit torque, the turning handle corotates upon motor operation of the lock or locking cylinder.
Opening of the lock with the gear motor can be started by an access control system. One can also provide a switch, e.g. a push button, on the escutcheon for operating the gear motor, or the gear motor can be operated by an external switch. The inventive drive apparatus opens the lock via the turning handle and draws the latch of the lock, if any. Control of the gear motor is performed by control electronics disposed externally on the escutcheon.
For detecting the rotary position of the drive-shaft, a position detecting device is provided which is connected with the driveshaft or driving toothed wheel so as to transmit torque. The position detecting device can be used to monitor the revolutions of the lock. Closing of the lock is effected automatically by the control electronics, depending on the adjusted parameters and the state of the position detecting device. Further sensors for position detection can also be provided, for example sensors which operate the gear motor for closing as soon as the door has fallen back into the frame.
The rotation axis of the turning handle is offset from the driveshaft, as are the motor shaft of the gear motor and at least the driven shaft of the gear. This eccentric, asymmetrical arrangement of the gear motor and turning handle makes it possible according to the invention to use a simply constructed motor gear with a short overall length and thus an accordingly short turning handle which receives the drive train comprising motor, gear and coupling.
The escutcheon preferably consists of a base plate and a drive receiving means to which the drive train comprising motor, gear and coupling is fastened. The drive receiving means, which is disposed in a recess of the base plate, can be assembled in different rotary positions relative to the base plate. This makes it possible to dispose the turning handle on the door leaf in an optimum position.
The coupling between the gear motor and the driving toothed wheel can be effected by an electromagnet or, alternatively, by operation of the gear motor.
In the case of electromagnetic coupling, one provides a coupling toothed wheel axially displaceable by an electromagnet and engaging, in the coupled position, the driving toothed wheel and a gear wheel rotating in unison on the driven shaft of the gear of the gear motor. In the uncoupled state with the electromagnet unenergized, however, the coupling toothed wheel is disengaged from the driving toothed wheel and/or the gear wheel. For this purpose the coupling toothed wheel can be spring-loaded to the uncoupled position.
If the coupling is operable by operation of the gear motor, one can provide an axially displaceable coupling toothed wheel on the driven shaft of the gear so as to rotate in unison, said wheel engaging the driving toothed wheel in the coupled position and being disengaged therefrom in the uncoupled position. In this embodiment the coupling toothed wheel is also spring-loaded to the uncoupled position.
In the case of mechanical coupling by operation of the gear motor, the axial displacement of the coupling toothed wheel can be effected by a dog on the driven shaft of the gear or the coupling toothed wheel and an oblique guide or sliding surface for the dog on the coupling toothed wheel or driven shaft of the gear. When the energizing of the gear motor is interrupted this causes automatic, currentless uncoupling of the gear motor from the driving toothed wheel since the uncoupling spring pushes the coupling toothed wheel back to its starting position. If no automatic uncoupling by the uncoupling spring is effected, uncoupling is effected at the latest by manual motion of the turning handle.
To prevent the gear motor from being damaged when hitting a stop in left- or right-hand motion one can provide a starting and stop shock absorber, for example a torsion spring, on one of the shafts between motor shaft and driveshaft.